Cigarette maker

ABSTRACT

In a cigarette maker, shredded tobacco is directed by a conveyor into a riser and ascends as a flow of distinct particles toward an aspirating belt, placed at the top outlet end of the riser, by which the particles are attracted and gathered progressively to form a stream of tobacco filler. The riser is made up of a lower first portion in receipt of the tobacco from the conveyor, and an upper second portion enclosed by the aspirating belt; the first portion is embodied separately from the second portion, and the two portions are inter-connected by the revolving surface of a toothed suction roller designed to transfer a uniform layer of tobacco from the first portion to the second.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a cigarette maker.

[0002] The prior art embraces cigarette making machines, with single ormultiple processing lines, typically comprising an infeed chamber fromwhich shredded tobacco is taken up by a carding unit and directed into adescent channel or chute.

[0003] At the bottom end of the chute, the tobacco is transferred by atoothed outfeed unit onto a feed conveyor and then carried by this sameconveyor toward the bottom inlet end of an ascending channel or riser.As the tobacco enters the inlet of the riser, stems and heavierparticles, or scraps, are separated from the lighter particles,whereupon the stems and scraps drop by gravity into a collection vesseland will be rejected, whilst the lighter particles, used in themanufacturing process, are carried up the riser on an ascending aircurrent.

[0004] The top end of the riser is enclosed by a single conveyor, in thecase of a machine with just the one processing line, or two conveyorsside by side in the case of a machine with two lines. Reference will bemade explicitly during the course of the following specification to acigarette maker with two lines, albeit implying no limitation in scope.

[0005] Each conveyor takes the form of a substantially horizontalair-permeable, aspirating belt capable of attracting the tobaccodirected up through the riser as a continuous flow of divided particles,and causing it to form gradually into a continuous stream of filler. Theflow of air ascending through the riser, which carries the tobacco uptoward the aspirating belts, is generated by negative pressure createdinternally of an elongated vacuum chamber enclosed on the underside bythe two belts. The streams of tobacco forming thus beyond the outlet ofthe riser are directed by the aspirating belts through a trimmingstation of which the function is to reduce the stream to a predeterminedand uniform thickness, or depth. The trimmed streams of tobacco are thenreleased by the aspirating belts to the entry point of a station wherethey are formed into two respective continuous cigarette rods.

[0006] As production tempo increases, cigarette makers of theconventional type in question betray certain drawbacks with regard inparticular to the correct formation of the tobacco stream on theaspirating belts. More exactly, a higher operating speed must beaccompanied necessarily, one the one hand, by a higher linear velocityof the aspirating belts, and on the other by a faster ascending movementof the tobacco particles within the riser.

[0007] For the tobacco particles to ascend more quickly through theriser as required, air must be drawn by the vacuum chamber through theaspirating belts at a higher rate of flow. A first consequence of suchan increase is that the aspirating belts are soon saturatedtransversely, as the tobacco will tend to accumulate non-uniformly inthe vertical direction, perpendicular to the belts, with the density ofthe particles at its greatest near the surface of the belts anddecreasing substantially in hyperbolic mode as the distance from thebelts increases. A second consequence is that of a more violent impactbetween the tobacco particles and the surfaces of the aspirating belts,which causes the particles to slip, roll and bounce against the beltsand results ultimately in an uneven and incorrect distribution of theparticles along the direction followed by the belts.

[0008] Another drawback tending to accompany the higher operating speedsof conventional cigarette makers described above is reflected in anunsatisfactory separation of the stems and the heavier scraps of tobaccofrom the lighter particles. In practice, the faster the tobacco isdirected into the riser, the shorter the duration of the separationprocess becomes, and with the area of the machine where the process inquestion takes place tending typically to be somewhat restricted, thestems and heavier scraps of tobacco are liable to be entrained in theupward current when air is drawn through the riser at high speed.

[0009] The object of the present invention is to provide a cigarettemaker unaffected by the aforementioned drawbacks.

SUMMARY OF THE INVENTION

[0010] The stated object is realized according to the present inventionin a cigarette maker comprising at least one ascent channel throughwhich to direct a flow of tobacco particles, a feed system by which thetobacco is supplied to the ascent channel, and at least one aspiratingbelt set in motion adjacent to the outlet of the ascent channel, onwhich the flow of particles is formed into a corresponding stream oftobacco. The ascent channel is composed of a lower first portiondesigned to receive the tobacco, and an upper second portion enclosed bythe belt, and can be equipped advantageously with conveyor meansinterposed between the first portion and the second portion, of whichthe function is to transfer a predetermined quantity of tobacco from theone portion to the other portion.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The invention will now be described in detail, by way of example,with the aid of the accompanying drawings, in which:

[0012]FIG. 1 illustrates a first embodiment of the cigarette makeraccording to the present invention, viewed schematically in a verticalsection;

[0013]FIG. 2 shows a first portion of the cigarette maker according tothe present invention, viewed schematically in a vertical section andillustrated in a second embodiment;

[0014]FIG. 3 is a variation on a detail of FIG. 2;

[0015]FIG. 4 shows a second portion of the cigarette maker according tothe present invention, viewed schematically in a vertical section andillustrated in the aforementioned second embodiment;

[0016]FIG. 5 shows the portion of FIG. 4 in a plan view, illustratedschematically and with certain parts cut away.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] With reference to FIG. 1, which illustrates a first embodiment ofthe cigarette maker according to the invention, and in particular amachine with a single processing line, 1 denotes an infeed portion, inits entirety, of such a machine.

[0018] The infeed portion 1 comprises a feed unit 2 by which a mass ofshredded tobacco is formed into a continuous flow of tobacco particles.The various components making up the feed unit 2 are housed within avertically extending enclosure 3 delimited uppermost by a horizontalwall 4 and on either side by two vertical walls 5 and 6.

[0019] The infeed portion 1 presents an inlet duct 7 extending upwardfrom the horizontal wall 4, and below the duct, internally of theenclosure 3, a power driven toothed roller 8 by which the shreddedtobacco 9 is directed down into a lower chamber 10 delimited at thebottom by a conveyor belt 11.

[0020] The chamber 10 accommodates a carding roller 12 rotatable aboutan axis 13 transverse to the side walls 5 and 6, forming part of acarding unit 14 and positioned adjacent to the downstream end of thebelt 11.

[0021] In addition to the carding roller 12, the unit 14 comprises aproportioning roller 15 rotatable substantially tangential to thecarding roller 12 and in the same direction.

[0022] With this arrangement, the shredded tobacco 9 is directed by thetoothed roller 8 onto the belt 11 and thence toward the carding roller12, whereupon a layer of the tobacco 9 substantially equal in thicknessto the radial dimension of the carding teeth is transferred by theroller 12 away from the chamber 10 and beyond its position of tangentialproximity to the proportioning roller 15.

[0023] The infeed portion further comprises an impeller roller 16rotatable about an axis parallel to the axis 13 aforementioned, of whichthe function is to pick up the layer of tobacco 9 from the cardingroller 12 and project the constituent particles, in the directiondenoted F1, down into a substantially vertical descent channel or chute17 delimited by two side walls 18 and 19 extending parallel one withanother and with the axis 13 of the carding roller 12.

[0024] The bottom end of the chute 17 is positioned facing the peripheryof a toothed take-up unit 20 that comprises a take-up roller 21 and animpeller roller 22 combining one with another to transfer the shreddedtobacco 9 away from the chute 17.

[0025] More exactly, the tobacco 9 is received by the take-up unit 20 inthe form of distinct particles and projected onto conveyor means 23 ofwhich the function is to direct the shredded material toward an ascentchannel or riser 24 enclosed at the top end by the moving surface of anaspirating belt 25 fashioned from air-permeable material.

[0026] In accordance with the present invention, the riser 24 is dividedinto a lower first portion 26 and an upper second portion 27, of whichthe top end 28 is enclosed by the aforementioned aspirating belt 25. Thetwo portions 26 and 27 are separated and interconnected by conveyormeans denoted 29 in their entirety, interposed between the outlet 30 ofthe first portion 26 and the inlet 31 of the second portion 27.

[0027] The length of the first portion 26, as measured along thedirection of movement of the belt 25, is identical to the correspondinglength of the second portion 27, whereas it will be seen from FIG. 1that the width of the first portion 26, measured transversely to thissame direction, is appreciably greater than that of the second portion27.

[0028] The aforementioned conveyor means 29 could be of any given type,and will be capable of transferring a predetermined quantity of tobacco9 between the outlet 30 of the first portion 26 and the inlet 31 of thesecond portion 27 of the riser 24.

[0029] In particular, the conveyor means 29 will consist in any suitableconveying device capable of motion along a path that describes anendless loop. In the example illustrated, such means take the form of atoothed roller 32 rotatable clockwise, as viewed in FIG. 1, about anaxis 33 parallel to the axis 13 of the carding roller 12, also to thedirection of movement of the aspirating belt 25, and connected to asource 34 of negatively pressurized fluid in such a way that suction canbe generated through the outer surface of the roller 32. Instead of aroller 32, alternatively, use could be made of a belt looped around aplurality of pulleys with axes parallel to the axis 13 of the cardingroller 12 and to the direction of movement of the belt 25.

[0030] In the case of the roller 32, the looped path appears as acircular circumference and includes a first sector 35, on which a layer36 of tobacco 9 is formed, and a second sector 37 from which theparticles 38 making up the layer 36 of tobacco 9 are released.

[0031] More exactly, the first sector 35 coincides with the part of theroller 32 extending upward from and along the outlet 30 of the firstportion 26 of the riser 24, whilst the second sector 37 coincides withthe part of the roller 32 extending along the inlet 31 of the secondportion 27 of the riser 24.

[0032] The path described by the toothed roller 32 also presents a thirdsector 39 interposed between the first and second sectors 35 and 37,occupied by metering and leveling means 40 which take the form of anequalizing roller 41 offered tangentially to the toothed roller 32. Theroller 41 in question is rotatable counterclockwise, as viewed in FIG.1, about an axis 42 extending parallel to the axis of the toothed roller32, and at a speed marginally different to that of the latter roller 32.In this way, the equalizing roller 41 is able to ensure a uniformthickness of the aforementioned layer 36 of tobacco by redistributingparticles from areas of greater density to areas of lesser density thatmay have formed in the layer.

[0033] As discernible in FIG. 1, the aforementioned lower first portion26 of the riser 24 terminates at the bottom end in a downwardly inclinedwall 43 of which the higher part is directed toward the conveyor means23 bringing the tobacco 9 from the toothed take-up unit 20.

[0034] The inclined wall 43 presents a plurality of holes 44 throughwhich to direct a pressurized fluid from a relative source denoted 45,of which the purpose will be described in due course.

[0035] The conveyor means 23 take the form of a first vibrating tray 46such as will slow the rate at which the tobacco advances toward theinlet of the first portion 26 of the riser 24.

[0036] Also associated with the toothed roller 32 at a point near theinlet of the upper second portion 27 of the riser 24, coincidingsubstantially with the second or release sector 37 of the looped path,are means denoted 47 by which to shut off the suction generated by thesource 34 of negative pressure, and/or means denoted 48 by which togenerate a flow of positively pressurized fluid. Such means 48 mightconsist, by way of example, in a nozzle 49 connected to a source 50 ofpressure and angled convergently with the direction of movement of theaspirating belt 25. The aspirating action of the belt 25 combines withthe dislodging flow blown by the nozzle 49, which includes a componentoriented along the feed direction of the belt 25, to bring about anefficient transfer of the particles 38 of tobacco 9 from the surface ofthe roller 32 to the belt 25.

[0037] Thus, the particles 38 cling to the aspirating belt 25 and formprogressively into a continuous stream (not illustrated), which onemerging from the second portion 27 of the riser 24 will advance on thebelt 25 toward successive stations (not illustrated) where it istrimmed, shaped and formed ultimately into a continuous cigarette rod.

[0038] It will be seen that, with the width of the first portion 26significantly greater than the width of the second portion 27, which issubstantially equal to that of the aspirating belt 25, and the width ofthe sector 35 on which the layer 36 of tobacco 9 is formed likewise muchgreater than the width of the aspirating belt 25, it becomes possiblewith only a relatively modest speed of rotation of the toothed roller 32about its axis 33 and a relatively modest velocity of the particles 38of tobacco 9 within the riser 24, for the belt 25 to be supplied withthe correct quantity of tobacco 9 even when running at relatively highspeed, and in such a manner as to guarantee a substantially uniformstratification of the tobacco 9 on the aspirating surface, both alongthe direction of movement of the belt 25 and in the vertical dimension,normal to the belt 25. Also, and to advantage, the process of separatingthe stems and larger scraps of tobacco 9 from the smaller particlesoccurs internally of a spacious enclosure afforded by the lower firstportion 26, with the tobacco particles substantially detached one fromanother and progressing at a comparatively gentle rate of motion. Thesuccession of selection jets delivered through the holes 44 also helpsto increase the efficiency of the process whereby the stems and heavierscraps of tobacco are separated out. The stems and heavier scraps 54drop into a collection trough 55.

[0039]FIGS. 2, 3 and 4 illustrate a second embodiment of the infeedportion 1 forming part of a cigarette maker according to the invention,and in particular a machine with two processing lines, that is to sayequipped with two aspirating belts 25 on which two identical streams oftobacco are formed.

[0040] As regards the structure and operation of the risers 24 and thetoothed rollers 32, it will be seen that there is no difference betweenthis and the single line embodiment of FIG. 1.

[0041] In particular, as illustrated in FIGS. 4 and 5, the infeedportion 1 of the machine comprises two risers 24 conveying tworespective flows of tobacco particles 38, and two aspirating belts 25located each above the top outlet end 28 of the relative second portion27 of a corresponding riser 24, on which the two flows of particles 38are formed into respective streams of tobacco 9.

[0042] More exactly, the risers 24 and the respective toothed rollers 32are disposed symmetrically on either side of a vertical plane 51 lyingbetween the two aspirating belts 25, as discernible in FIGS. 4 and 5,and positioned transversely to the axes of rotation of the cardingroller 12 and of the take-up roller 21, as illustrated in FIG. 5. In thesolution of FIGS. 2 to 5, more exactly, the toothed conveying rollers 32are centered on respective axes 33 rotated through an angle of 90°(ninety degrees) relative to the viewing plane of the drawings, ascompared to the position of the single roller 32 illustrated in FIG. 1,where the axis 33 of rotation extends parallel to the axis of thecarding roller 12.

[0043] In the example of FIG. 5, the tobacco 9 is carried from thetake-up roller 21 toward the two risers 24 by conveyor means 23comprising a common first portion 52 and a pair of mutually independentsecond portions 53. The two independent portions 53 extend divergentlyfrom the common portion 52 and on either side of the vertical plane ofsymmetry, in such a way that the particles 38 of tobacco 9 are carriedtoward respective inclined walls 43 presented by the two lower firstportions 26 of the corresponding risers 24.

[0044] In like manner to the example of FIG. 1, each of the two inclinedwalls 43 in this embodiment will present a plurality of holes 44 fromwhich to generate a succession of air jets designed to aid the efficientseparation of any stems and heavier scraps 54 of tobacco from thelighter particles. Here again, the stems and scraps 54 drop into acollection trough 55.

[0045] In particular, both the common first portion 52 and theindependent second portions 53 consist in respective vibrating trays 56and 57.

[0046] In the example of FIG. 2, the particles 38 of tobacco 9 leavingthe take-up roller 21 drop onto a conveyor 58 moving from right to leftas viewed in FIG. 2, and angled upward in such a manner that theforwardmost edge will be positioned over the vibrating tray 56constituting the common first portion 52.

[0047] Thus, the particles 38 of shredded tobacco 9 are advanced at asuitably measured rate of feed toward the two bottom walls 43 presentedby the two first portions 26 of the risers 24. Here, the stems andscraps 54 are separated and the lighter particles are directed upwardthrough the first portions 26 in a continuous flow, entrained in acurrent of air generated by pneumatic means of familiar embodiment (notillustrated). On reaching the first sector 35 of each toothed roller 32set in rotation about the relative axis 33, the flow of tobaccoparticles 38 will thicken progressively and at low speed on the surfaceof the roller 32 passing momentarily over the outlet 30 of the firstportion 26, forming into a layer 36. Each layer 36 of tobacco isdistributed and spread by the relative equalizing roller 41 and advancesgradually toward the second sector 37 of the roller 32. At this point,the suction shut-off means 47 and/or the nozzles 49 are activated, sothat the layer 36 of tobacco 9 is caused to detach from the surface ofthe roller 32 and gather into a new flow of particles 38. Exposed to thecombined action of the aspirating belts 25 and of the jets delivered bythe relative nozzles 49, the released particles will cling progressivelyto the belts 25 and form into a continuous stream of tobacco on eachone.

[0048] Finally, it will be seen in the illustration of FIG. 3 that theparticles 38 of tobacco 9 are released by the rollers 21 and 22 directlyonto the common vibrating tray 56.

1) A cigarette making machine, comprising: at least one ascent channelthrough which to direct at least one flow of tobacco particles; conveyormeans by which tobacco is supplied to a lower first portion of theascent channel; at least one aspirating belt enclosing and set in motionadjacent to the outlet of an upper second portion of the ascent channel,on which the flow of particles is formed into a corresponding stream oftobacco; means, interposed between the first portion and the secondportion of the ascent channel, by which to convey a predeterminedquantity of tobacco from the first portion to the second portion. 2) Acigarette making machine, comprising: a descent channel; feed means bywhich shredded tobacco is supplied to the descent channel; a unit bywhich the tobacco is taken up from the descent channel; at least oneascent channel through which to direct at least one flow of tobaccoparticles, comprising a lower first portion and an upper second portionembodied separately one from the other; conveyor means by which thetobacco is transferred from the take-up unit to the first portion of theascent channel; at least one aspirating belt enclosing and set in motionadjacent to the outlet of the upper second portion of the ascentchannel, on which the flow of particles is formed into a correspondingstream of tobacco and the stream then directed to the entry point of astation where it is formed into a continuous cigarette rod; means,interposed between the first portion and the second portion of theascent channel, by which to convey a predetermined quantity of tobaccofrom the first portion to the second portion. 3) A machine as in claim 1or 2, wherein the length of the first portion, as measured along thedirection of movement of the aspirating belt, is identical to thecorresponding length of the second portion, whereas the width of thefirst portion, measured transversely to the selfsame direction, isgreater than that of the second portion. 4) A machine as in claim 1,wherein the conveyor means are capable of movement along an endless pathincluding a first sector adjacent to an outlet presented by the firstportion of the ascent channel, on which a layer of tobacco is formed,and at least one second sector, adjacent to an inlet presented by thesecond portion of the ascent channel, from which the particlesconstituting the layer of tobacco are released. 5) A machine as in claim4, comprising means by which to level the layer of tobacco, operating inconjunction with a third sector of the conveyor means interposed betweenthe first and second sectors. 6) A machine as in claim 2, wherein feedmeans comprise a carding roller rotatable about a relative axis, andconveyor means comprise a toothed roller able to generate suction androtatable about a respective axis disposed substantially parallel to theaxis of the carding roller. 7) A machine as in claim 1, wherein conveyormeans comprise a toothed roller able to generate suction and rotatableabout a respective axis disposed substantially parallel to the directionof movement of the aspirating belt. 8) A machine as in claim 5, whereinleveling means consist in a roller occupying a position substantiallytangential to the toothed roller. 9) A machine as in claim 5, whereinleveling means consist in a roller occupying a position substantiallytangential to the toothed roller. 10) A machine as in claim 1, whereinthe conveyor means comprise at least one vibrating tray. 11) A machineas in claim 2, wherein the conveyor means used to transfer the tobaccocomprise at least one vibrating tray. 12) A machine as in claim 2,comprising feed means equipped with a carding roller rotatable about arespective axis, two ascent channels through which to direct respectiveflows of tobacco particles, and two aspirating belts placed at theoutlets of the ascent channel, on which the flows are formed intocorresponding streams of tobacco, wherein the two ascent channels arearranged symmetrically on either side of a vertical plane lying betweenthe aspirating belts and perpendicular to the axis of rotation of thecarding roller. 13) A machine as in claim 12, wherein the conveyor meansby which the tobacco is transferred comprises a common first portion andtwo mutually independent second portions extending divergently from thecommon first portion on either side of the vertical plane of symmetry.14) A machine as in claim 13, wherein the common first portion and thetwo mutually independent second portions consist in respective vibratingtrays. 15) A machine as in claim 12, wherein each ascent channel isequipped with a respective toothed conveyor roller able to generatesuction and rotatable about a respective axis disposed transversely tothe axis of the carding roller. 16) A machine as in claim 1, comprisingtwo ascent channels through which to direct two flows of tobaccoparticles, and two aspirating belts positioned at the outlets of theascent channels, on which the flows of particles are formed intocorresponding streams of tobacco, wherein the ascent channels arearranged symmetrically on either side of a vertical plane lying betweenthe aspirating belts, and equipped each with a relative toothed conveyorroller able to generate suction and rotatable about a respective axisdisposed substantially parallel to the direction of movement of theaspirating belts. 17) A machine as in claim 4, wherein the conveyorroller able to generate suction comprises means, associated with thesecond release sector, by which to shut off the suction. 18) A machineas in claim 17, comprising means, associated with the second releasesector, by which to generate a flow of positively pressurized fluid. 19)A machine as in claim 1, wherein the first portion of the ascent channelterminates at bottom in an inclined wall presenting holes through whichto direct a pressurized fluid. 20) A method of making cigarettes,comprising the steps of: directing a flow of shredded and carded tobaccoparticles down a descent channel; taking up the shredded tobacco at thebottom of the descent channel by means of a toothed unit andtransferring it by way of conveyor means to the inlet of at least oneascent channel; establishing a first flow of tobacco particles andcausing to rise through the ascent channel; forming a layer of tobaccofrom the ascending flow of particles at the outlet of a first portion ofthe ascent channel; transferring the layer of tobacco to the inlet of asecond portion of the ascent channel; establishing a second ascendingflow of particles from the layer of tobacco and directing the secondflow toward at least one aspirating belt placed at the outlet of theselfsame channel; causing the particles to form into a continuous streamon the aspirating belt. 21) A method as in claim 20, wherein the step oftransferring the layer of tobacco comprises the subsidiary step ofleveling the selfsame layer of tobacco.